Meibomian Gland Features and Conjunctival Goblet Cell Density in Glaucomatous Patients Controlled With Prostaglandin/Timolol Fixed Combinations: A Case Control, Cross-sectional Study

Purpose: To investigate, using in vivo confocal microscopy (IVCM), the Meibomian gland (MG) features and conjunctival goblet cell density (GCD) in glaucomatous patients controlled with prostaglandin/timolol fixed combinations (PTFCs). Materials and Methods: In this cross-sectional study, 60 white patients were treated with PTFCs, 15 with latanoprost+timolol (L+T) unfixed combination, and 15 controls were enrolled. Patients underwent the Ocular Surface Disease Index questionnaire, tear film breakup time, corneal staining, Schirmer test I, and IVCM of MGs and goblet cells. The main outcome measures were: mean Meibomian acinar density (MMAD) and area (MMAA), inhomogeneity of glandular interstice (InI) and acinar wall (InAW), and GCD. Results: PTFCs were: latanoprost/timolol (LTFC, 15 eyes), travoprost/timolol (TTFC, 15), bimatoprost/timolol (BTFC, 15), and preservative-free bimatoprost/timolol (PF-BTFC, 15) fixed combinations. Mean time on therapy did not differ among treatments. IVCM documented lower GCD, MMAD, and MMAA (P<0.001), and greater InI and InAW (P<0.05) in glaucoma patients compared with controls. L+T showed worse values compared with PTFCs and PF-BTFC (P<0.05). Preserved PTFCs showed lower MMAD, MMAA, GCD, and greater InI and InAW compared with PF-BTFC (P<0.05) and controls (P<0.001). Differences were not found among PTFCs. InI and InAW significantly correlated with Ocular Surface Disease Index and breakup time (P<0.001), corneal staining (P<0.05), and GCD (P<0.001); GCD correlated with MMAD (P<0.05). Conclusions: PTFCs were less toxic towards MGs and goblet cells compared with the L+T unfixed combination, with PF-BTFC presenting the most tolerated profile. These findings should be carefully considered given the role of these structures in the induction of the glaucoma-related ocular surface disease.